If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below. |
|
|
|
Thread Tools | Display Modes |
#1
|
|||
|
|||
A PIREP: engine-out turn-back - some practice in the haze
On Mon, 13 Jun 2005 10:07:55 -0400, T o d d P a t t i s t
wrote: I had no trouble turning back 180 degrees from 200', just as I do in my glider. A rapid push to get the nose down and maintain speed, and a rapid roll to about 40 degrees of bank. Lots of back stick pressure. I never had to let the airspeed drop below 60 mph. By the time it was turned back, I still had 50-75' left to make a shallow alignment turn. 200 ft is impressive. What is your sink rate (fpm) at best glide? |
#2
|
|||
|
|||
"T o d d P a t t i s t" wrote in message ... It was seriously hazy this weekend, and with a long cross country coming up in our 1946 Aeronca Champ, I thought it was a good day to do some engine-out landing practice. I was flying with full fuel, but solo. Wind was light, 3 knots or less. Field elevation was below 1000' MSL, temp about 77 deg F/ near 100. For those not familiar with the Champ, it's a 65 hp taildragger with a max gross of 1220 pounds. I was flying it 150 pounds under that. After some ordinary engine-out landings from downwind and base I began to practice engine-out turn-back from the initial climb out on takeoff. I thought others here might be interested in my results. Good Stuff here, Todd. I haven't worked up the nerve to do the same work in the 172, except at altitude. My perceived threshold is 500 feet with the Skyhawk. My plan is to start above that and work down. At least until I'm comfortable with the results. Thanks for posting this. |
#3
|
|||
|
|||
Todd,
Interesting what may be done in a low wing loading airplane. In many flight test protocols, the procedure is for the pilot to wait a full three seconds after an engine failure to take any action. The idea is to simulate the normal reaction time for someone who is not expecting an engine failure and goes through the mental exercise to accept that it's happening and finally take action. By any chance did you do that, or did you start your procedure immediately upon reducing power? All the best, Rick T o d d P a t t i s t wrote: It was seriously hazy this weekend, and with a long cross country coming up in our 1946 Aeronca Champ, I thought it was a good day to do some engine-out landing practice. I was flying with full fuel, but solo. Wind was light, 3 knots or less. Field elevation was below 1000' MSL, temp about 77 deg F/ near 100. For those not familiar with the Champ, it's a 65 hp taildragger with a max gross of 1220 pounds. I was flying it 150 pounds under that. After some ordinary engine-out landings from downwind and base I began to practice engine-out turn-back from the initial climb out on takeoff. I thought others here might be interested in my results. I had no trouble turning back 180 degrees from 200', just as I do in my glider. A rapid push to get the nose down and maintain speed, and a rapid roll to about 40 degrees of bank. Lots of back stick pressure. I never had to let the airspeed drop below 60 mph. By the time it was turned back, I still had 50-75' left to make a shallow alignment turn. There was certainly no time to waste, but with practice it was a comfortable maneuver. Of eight attempts, I would have been in the trees once and the bushes once. The trees are in a line at one end of the runway, with a cut through them in line with the runway. My first attempt I didn't go far enough to the side during the climb out, so when I turned, I couldn't get back through the cut. All the other attempts in that direction I let myself slide off to the side so I could turn back through the cut. One time I came through the cut and had to land diagonally on the grass adjacent the departure runway. If I wanted to land on the same runway, with no crosswind, I needed to get really far to the side during the climb out. The time I would have ended in the bushes at the opposite end occurred because I did a touch and go from the previous attempt. That put me farther down the runway than usual, so on the 180 reverse, although I was turned back, wings level and aligned, I couldn't glide far enough to get back to the runway over the bushes in the overrun. This is not a recommendation to anyone else as to the altitude to turn back at. This was one specific light airplane, flown solo, using a modified departure to put me in the best position to turn back, by a pilot who knew exactly when the engine would "fail" and who was current in engine out and had lots of 200' turn back practice in gliders. I have seen lots of other reports of heavier aircraft practicing turn backs and estimating more than 600 - 800' needed for success. I watched a friend lose an engine in a very similar aircraft at a similar height. He turned back, following a very similar flight path to the ones described above, and hit a dead tree. Do not spin this aircraft. If the aircraft does enter a spin it will return to earth without further attention on the part of the aeronaut. (first handbook issued with the Curtis-Wright flyer) |
#4
|
|||
|
|||
"T o d d P a t t i s t" wrote in message ... .... After some ordinary engine-out landings from downwind and base I began to practice engine-out turn-back from the initial climb out on takeoff. I thought others here might be interested in my results. I had no trouble turning back 180 degrees from 200', ...snip... http://www.aopa.org/asf/publications...m?article=2911 |
#5
|
|||
|
|||
Todd,
Thanks fort the additional information. This is, sadly, a subject that has been explored in aviation since the early days of the Wrights. No matter how many times we hammer on pilots not to turn back to the runway, a huge proportion of them insist on trying, even if they have never, ever practiced the maneuver (um, lessee, I've got a full-fleged emergency, I'll try something I've never practiced before...Doh), and a staggeringly high percentage of those who try it, die or get seriously injured. I worked a matter about 10 years ago involving a pilot who lost the engine on a Cessna 150 at somewhere around 400 feet and tried to return; he survived the crash but has serious brain damage. (Roughly half of the pilots faced with an engine out forced landing stall the airplane at up to 20 feet AGL, sometimes higher, especially if in a turn-which reduces their chance of survival measurably. That pilot stalled at an undetermined altitude.) I'm also interested in the amount of time it takes a pilot to react to a power loss. With pilots on flight reviews, I've seen some of them sit there and do nothing or "swim in glue" for as much as 10 seconds before taking meaningful, effective action. I've had more than one event in which an engine quit and in each one there was a period of "this can't be happening" thinking before I dealt with it - don't know how long it was - on one twin during the takeoff roll it was long enough to get pretty close to the edge of the runway, and I used every bit of the runway getting stopped. There have been a number of serious academic studies on the subject of the best turnaround procedure for minimum altitude loss, and it seems to involve a fairly steep bank-on the order of 60 degrees if I recall correctly. The problem is, as aerobatic and ag pilots know, practicing that maneuver at altitude is different than doing it down low; the world looks different below 500 feet, the horizon is subtly different and it can bite a person unless it has been practiced - recently. You have, IMHO, a major advantage over most pilots in that you have glider experience, and, I suspect, the idea of your engine taking the day off is not nearly as traumatic on a very visceral level. Nevertheless, from the point of recent experience, if you had not practiced a rerturn maneuver within the last 6 months and lost the engine of the Champ at 250 feet AGL, would you be willing to bet your life you could pull off the return maneuver successfully the very first time g? Based on the fact that you have just practiced the return maneuver, can you put a number on the minimum altitude AGL at which you'd attempt it for real if you had to today? Would that number change if you hadn't practiced it for 3 months? (I'm curious, as my own "minimums" for various events get more conservative as the time since my last recurrent training gets longer.) Thanks again for putting up your experience. All the best, Rick |
#6
|
|||
|
|||
T o d d P a t t i s t wrote: I witnessed a turnback in a similar aircraft that was close enough to be called a partial success. He would have made it with a slightly wider runway, and his alternatives were all much worse. There is a limit at which it can be done successfully, and a limit where it can't. I think it's valuable to know that limit, and I'd already gone through the "what-ifs" at altitude. I knew "pattern altitude" was way too high for the Champ. It was time to try it for real. IMHO, You've got the right idea. The blanket "don't turn back unless you're at pattern altitude" may not always be the best option. It's important to know what you and your plane are capable of doing. As you noted, the best alternative may not include getting back to a runway. At airports that are surrounded by densely populated suburbs, often the best place to be is somewhere in the airport environment that is relative free of obstructions like houses and schools. If you can make it back this area, you may be better off even if you can't make a runway. John Galban=====N4BQ (PA28-180) |
#7
|
|||
|
|||
T o d d P a t t i s t wrote: snip ... I know some may feel I should keep silent for fear of encouraging others to do that which will kill them. snip Encouraging others to go out and carefully experiment in a controlled environment and learn what the REAL numbers are for THEIR skill and comfort levels and THEIR equipment is nothing but good, IMHO. -R |
#8
|
|||
|
|||
The Idea is to give the pilot primative instructions that are easy to fall back on in very bad situations. Keep the rules simple and easy to follow. In the glider the student is taught exactly what power pilots are taught with a modification. In the Glider below 200 feet land straight ahead. In a power plane always land straight ahead when departing. We perhaps fall down a bit on the explanation for power pilots. Most power pilots turn Crosswind at about 500'. In most airplanes and most airports this is about the point where the turn can be made back to runway with average skill. It is also high enough that most power pilots can judge if they can make it back or not and have some time to make that decision. Plus they can see the runway from this point to make that decision. So we tend to simplify this to just don't turn back on departure. It is simple and easy to recall when your airplane unexpectedly becomes a glider. The Champ is a neat airplane I have given about 400 hours of instruction in them. But as you point out you were in the Ideal situation. 1. You knew the engine was going to quit. Although a good pilot is always expecting that. 2. You moved downwind (I assume) so that only 180 degree turn was required. 3. you are in a light slow airplane with a tight turning radius. 4. you kept your speed up during the climb out. Other factors to consider. If aligned with the runway when the engine quits you must do 360 degrees of Turn. 270 followed by a 90 of some something simlar (225, straight then 45) Ground Ilusions and Wind. How many people know what it looks like to do a downwind turn at 150 feet. It looks like you are going very fast when you are not. I Watched a Champ Stall spin due to this. Try doing some downwind approaches and Go Arounds with a 10-15kt tailwind. Be prepared for some very flat climb angles and keep you airspeed up. It will look like you are going fast when you are not. G-Loading- You are doing a steep turn you pulling G's. The Stall speed increases during the Turn. G-unloading - Ever notice the tendency to Climb after doing a 360 degree steep turn. Somehow your brain interpretes this unloading as not natural and you will unconsously tend to pull up and slow down even if you are alreadu slow. Several Glider stall/spin accidents have been attributed to this phenomea after low passes and pull up's. Cross wind- Gliders usually pay attention to this because turning into the wind can really help keep you close to the runway, Turning downwind can push you away from it. Thanks for reporting your finding. I firmly believe the more experience you have the better pilot you can be. Your practice has the potential to make you a much better pilot. Now I would suggest you try the test flying straight off the Runway at your best rate of climb speed. Wait the 3-4 seconds because you are going to have to decide if a turn is the best thing to do. and then try landing back on the 150ft wide runway you departed. My Guess is with this critera that you will find the 400 feet is probably the minumum you want even in the Champ (Try left and right turns). if you are turning crosswind at 500 feet it is easy to simplfy the issue to just don't turn back on departure. Crosswind Maybe Downwind almost Definintly. Brian CFIIG/ASEL HP16T |
#9
|
|||
|
|||
I don't want to crash into the trees when I have twice
the altitude I need to safely turn back simply because I was told to wait until pattern altitude. Well stated. Note that 200' in a glider is not that low. In fact in most gliders it probably has a saftey factor of about 2 to compensate for variables such as wind, runways and location from the runway. My typical issue with the 200ft turn around is that I am usually lined up with the runway going downwind with a 100 ft to spare and down wind It can sometimes take a little effort to not go off the far end of the runway. I would suggest you try the turn back scenero under some less than Ideal situations and then double that altitude you deem required for a turn back. Keep it simple and with lots of room for error. Brian |
#10
|
|||
|
|||
I don't want to crash into the trees when I have twice
the altitude I need to safely turn back simply because I was told to wait until pattern altitude. Well stated. Note that 200' in a glider is not that low. In fact in most gliders it probably has a saftey factor of about 2 to compensate for variables such as wind, runways and location from the runway. My typical issue with the 200ft turn around is that I am usually lined up with the runway going downwind with a 100 ft to spare and down wind It can sometimes take a little effort to not go off the far end of the runway. I would suggest you try the turn back scenero under some less than Ideal situations and then double that altitude you deem required for a turn back. Keep it simple and with lots of room for error. Brian |
|
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
AOPA Stall/Spin Study -- Stowell's Review (8,000 words) | Rich Stowell | Aerobatics | 28 | January 2nd 09 02:26 PM |
Long flight today... | Steve R. | Rotorcraft | 1 | October 21st 04 11:16 PM |
Pirep: Garmin GPSMAP 296 versus 295. (very long) | Jon Woellhaf | Piloting | 12 | September 4th 04 11:55 PM |
Weather vs. Combat | Gordon | Military Aviation | 38 | September 23rd 03 04:11 PM |
Corky's engine choice | Corky Scott | Home Built | 39 | August 8th 03 04:29 AM |